The options for a quick caffeine boost keep pouring in.
The energy drink industry is projected to reach nearly $20 billion in sales this year thanks to its most popular customer: teenagers.
But according to new research, that energy burst comes with a consequence: potentially dangerous health problems, especially among teens and young adults.
That has experts concerned.
Dr. Mary Claire O'Brien is one of 18 researchers who recently petitioned the Food and Drug Administration to restrict caffeine in energy drinks because they could be dangerous for young adults.
"They are more sensitive to the effects of caffeine, in part because their body mass is lower and in part because majority of them are are caffeine naive compared to adults," O'Brein explains.
A new study shows energy drinks have an immediate impact on heart rhythm and cause an increase blood pressure.
While most adults can tolerate this slight change in heart rate, teens' inexperience with caffeine makes their reaction stronger, with the potential to cause severe cardiac events especially among those with heart problems.
Many energy drinks are classified as dietary supplements, and therefore have no limit to the amount of caffeine they can contain -- unlike sodas.
"We don't think its safe based on the science, and we don't agree that the case has been made by the manufacturers that the levels are safe," O'Brein argues.
The American Beverage Association says research shows teens and young adults consume, on average, a third of the amount of caffeine as people over 21.
The FDA says evidence suggests it may be advisable for teens to limit their caffeine consumption. They are assembling a panel of experts to discuss the topic.